The present invention relates to nucleus-extended perylenebisimides of general formulae (I) and (II) 
wherein
R1 and R2 are each independently of the other unsubstituted or substituted C1-C24alkyl, C1-C24cycloalkyl, or C6-C10aryl, and
A1 and A3 are each independently of the other xe2x80x94Sxe2x80x94, xe2x80x94Sxe2x80x94Sxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, R3OOCxe2x80x94C(xe2x80x94)xe2x95x90C(xe2x80x94)xe2x80x94COOR3, xe2x80x94Nxe2x95x90Nxe2x80x94 or xe2x80x94N(R4)xe2x80x94, or a linkage selected from the group consisting of the organic radicals of formulae (III), (IV), (V), (VI) and (VII) 
wherein
R3 is hydrogen, C1-C24alkyl or C1-C24cycloalkyl,
R4 is unsubstituted or substituted C1-C24alkyl, C1-C24cycloalkyl, phenyl, benzyl, xe2x80x94COxe2x80x94C1xe2x80x94C4alkyl, xe2x80x94COxe2x80x94C6H5 or C1-C4alkylcarboxylic acid (C1-C4alkyl) ester, and
A2 is a linkage of formula (III), (IV) or (V),
also to intermediates for the preparation of compounds (I) and (II) and to processes for the preparation of those intermediates and also to processes for the preparation of compounds (I) and (II), and to the use thereof as colourants.
Perylenes, as is known (see Heterocycles, Vol. 40, No. 1, (1995) 477-500), are photostable fluorescent dyes that are often distinguished by high fluorescence quantum yields. A disadvantage thereof is, however, that perylenes have a low degree of solubility in aqueous media.
Chem. Ztg. (1975), 99, 92-93 describes, inter alia, nucleus-extended perylenes that are obtainable by Diels-Alder reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with perylene and that may exhibit absorptions at 600 nm.
Further Diels-Alder reactions on perylenes are described in Heterocycles, Vol. 40, No. 1, 1995. J. Org. Chem. USSR, (1986), 22, 943-946 describes the preparation of thio- and dithio-cyclic derivatives of perylene-3,4,9,10-tetracarboxylic acid. Furthermore, J. Org. Chem. USSR, (1980), 16, 762-7 describes a process for the preparation of nitrogen-cyclic derivatives of perylene-3,4,9,10-tetracarboxylic acid.
The problem underlying the invention was accordingly to provide further nucleus-extended perylenes, especially nucleus-extended perylenebisimides, that preferably as fluorescent dyes have good fastness to heat and to light; perylenes suitable as NIR dyes or as fluorescent markers were also to be provided.
Accordingly, there have been found the nucleus-extended perylenebisimides of general formulae (I) and (II) defined at the beginning.
C1-C24Alkyl is, for example, methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tert-butyl, n- or neo-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, heneicosyl, docosyl or tetracosl, preferably 1-(C1-C9alkyl)-C2-C10alkyl, such as 1-methyl-ethyl, 1-ethyl-n-propyl, 1-n-propyl-n-butyl, 1-n-butyl-n-pentyl, 1-n-hexyl-1-n-heptyl, 1-n-heptyl-1-n-octyl, 1-n-octyl-1-n-nonyl or 1-n-nonyl-1-n-decyl, or C1-C8alkyl, such as methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tert-butyl, n- or neo-pentyl, n-hexyl, n-heptyl or n-octyl and especially C1 -C4alkyl, such as methyl, ethyl, n- or iso-propyl or n-, iso-, sec- or tert-butyl.
C3-C14Cycloalkyl is, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, cyclotridecyl or cyclotetradecyl, preferably C5-C8cycloalkyl, such as cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl.
Especially preferred compounds of formulae (I) and (II) are those wherein R1 and/or R2 denote a secondary alkyl radical, such as 1-(C1-C9alkyl)-C2-C10alkyl, especially those wherein the radical R1has a so-called xe2x80x9cswallowtail structurexe2x80x9d, such as 1-methyl-ethyl, 1-ethyl-n-propyl, 1-n-propyl-n-butyl, 1-n-butyl-n-pentyl, 1-n-hexyl-1-heptyl, 1-n-heptyl-1-n-octyl, 1-n-octyl-1-n-nonyl, 1-n-nonyl-1-decyl, or an aromatic radical, especially the phenyl radical, very especially C1-C6alkyl-substituted phenyl, such as 2,6-di-tert-butylphenyl and 2,5-di-tert-butylphenyl.
C6-C10Aryl is, for example, phenyl or 1- or 2-naphthyl, especially phenyl.
xe2x80x94COxe2x80x94C1-C4Alkyl is xe2x80x94CO-methyl, xe2x80x94CO-ethyl, xe2x80x94CO-n-propyl, xe2x80x94CO-isopropyl, or xe2x80x94CO-n-, xe2x80x94CO-iso-, xe2x80x94CO-sec- or xe2x80x94CO-tert-butyl.
C1-C4Alkylcarboxylic acid (C1-C4alkyl) ester is, for example, methylcarboxylic acid methyl ester, methylcarboxylic acid ethyl ester, methylcarboxylic acid n-propyl ester, methylcarboxylic acid isopropyl ester, methylcarboxylic acid n-butyl ester or methylcarboxylic acid isobutyl ester, methylcarboxylic acid sec-butyl ester or methylcarboxylic acid tert-butyl ester or ethylcarboxylic acid methyl ester, ethylcarboxylic acid ethyl ester, ethylcarboxylic acid n-propyl ester, ethylcarboxylic acid isopropyl ester, ethylcarboxylic acid n-butyl ester, ethylcarboxylic acid sec-butyl ester or ethylcarboxylic acid tert-butyl ester, n-propylcarboxylic acid methyl ester or n-butylcarboxylic acid methyl ester.
Hal is, for example, halide and denotes fluoride, chloride, bromide or iodide.
Especially preferred perylene-3,4:9,10-tetracarboxylic acid bisimides of general formulae (I) and (II) are those wherein R1 and R2 are each independently of the other 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl, 1-nonyl-1-decyl or 1-n-butyl-n-pentyl; very especially R2 is R1.
Very special preference is given to perylene-3,4:9,10-tetracarboxylic acid bisimides of general formulae (I) and (II) wherein A1 is xe2x80x94Sxe2x80x94, NR4, xe2x80x94CHxe2x95x90CHxe2x80x94, R3OOCxe2x80x94C(xe2x88x92) xe2x95x90C(xe2x88x92)xe2x80x94COOR3, or a linkage of formula (III), (IV), (V), (VI) or (VII) and A2 and A3 are an organic radical of formula (V) or A2 and A3 are each independently of the other an organic radical of formula (III), (IV) or (V).
Preferred perylenes of the present invention are the compounds of formulae (VIII) to (XX) given below, wherein R1 and R2 are especially each independently of the other 1-hexyl-1-heptyl, 2,5-di-tert-butylphenyl, 1-nonyl-1-decyl or 1-butyl-pentyl, 
very especially R1 and R2 in (VII) are 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl or 1-butylpentyl, and 
wherein very especially R1 and R 2 are 1-n-hexyl-1-heptyl, and 
wherein preferably
R4 is unsubstituted or substituted C1-C24alkyl, C1-C24cycloalkyl, phenyl, and especially cyclohexyl or 2,5-di-tert-butylphenyl, and
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein
R1 and R2 are very especially 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl or 1-n-butyl-n-pentyl, and 
wherein preferably
R4 is unsubstituted or substituted C1-C24alkyl, phenyl, benzyl, xe2x80x94COxe2x80x94C1-C4alkyl, xe2x80x94COxe2x80x94C6H5 or C1-C4alkylcarboxylic acid (C1-C4alkyl) ester, and especially C1-C4alkyl, more especially methyl, benzyl, xe2x80x94CH2COOC2H5, xe2x80x94COCH3 or xe2x80x94CO-phenyl, and
R1 and R2 are very especially 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl or 1-n-butyl-n-pentyl, and 
wherein
R1 and R2 are very especially 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl or 1-n-butyl-n-pentyl, and 
wherein
R1 and R2 are very especially 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl or 1-n-butyl-n-pentyl, and 
wherein especially
R4 is substituted or unsubstituted phenyl, and
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein preferably
R3 is C1-C4alkyl, especially methyl or ethyl, and
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein especially
R4 is phenyl, and
R1 and R2 are very especially 1-n-hexyl-1-heptyl, and 
wherein especially
R4 is phenyl, and
R1 and R2 are very especially 1-n-hexyl-1-heptyl.
The perylenebisimides (I) according to the invention wherein A1 is A4, wherein A4 is a linkage selected from the group consisting of the organic radicals of formulae (III), (IV), (V) and (VII), and perylenebisimides (II) wherein A2 is A5, wherein A5 is a linkage of formula (III) or (V), and A1 is A6, wherein A6 is a linkage of formula (V), are preferably obtained by Diels-Alder reactions, as described in J.Chem.Soc. (1957), 96, 5616-4619.
The present invention accordingly relates also to a process for the preparation of perylenebisimides (I) wherein A1 is A4, wherein A4 is a linkage selected from the group consisting of the organic radicals of formulae (III), (IV), (V), (VII) and xe2x80x94Nxe2x95x90Nxe2x80x94, by Diels-Alder reaction of a diene with a dienophile at elevated temperature, wherein there are reacted, as diene, a perylenebisimide of formula (XXI) 
and, as dienophile, a compound selected from the group consisting of the compounds of formulae (XXII), (XXIII) and (XXIV) 
The order in which the starting materials (XXI) and (XXII), (XXI) and (XXIIa), or (XXI) and (XXIII), or (XXI) and (XXIV), are added is not generally important. It has, however, proved to be advantageous to use a compound of formula (XXII), (XXIIa), (XXIII) or (XXIV) as the initial charge and then to add the compound (XXI).
The compounds of formulae (XXII), (XXIIa), (XXIII) and (XXIV) are generally used in excess, preferably in a molar ratio of compounds (XXII):(XXI), (XXIIa):(XXI), (XXIII):(XXI) or (XXIV):(XXI) in the range of from 1.1:1 to 20:1, especially from 1.3:1 to 15:1.
The reaction is preferably carried out at a reaction temperatures in the range of from 80 to 200xc2x0 C., especially from 100 to 150xc2x0 C. According to observations hitherto, the success of the reaction is not dependent upon the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 4 weeks, especially in the range of from one day to 4 weeks.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, dipolar aprotic solvents, such as acetonitrile, benzonitrile, N,Nxe2x80x2-dimethylformamide, N,Nxe2x80x2-dimethylacetamide, nitrobenzene, N-methylpyrrolidone, aliphatic hydrocarbons, which may if desired be halogenated, such as trichloroethane, dichloroethane, trichloromethane or dichloromethane, or cycloalkanes, such as cyclohexane or cycloheptane, or aromatic hydrocarbons or mixtures thereof, such as benzine (as a mixture of different, essentially aliphatic hydrocarbons), or unsubstituted or alkyl-, alkoxy- or halo-substituted benzene, such as toluene, xylene, anisole or chlorobenzene, and also ethers, such as tetrahydrofuran, dioxane or EtOCH2CH2OH (e.g. in the form of Cellosolve(copyright) commercially available from Fluka) or glycol ethers, such as ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol monomethyl ether or diethylene glycol monoethyl ether, or nitrogen-containing solvents, such as pyridine, triethylamine, picoline or quinoline, and keto-group-containing solvents, such as acetone or methyl ethyl ketone. The above-mentioned solvents may also be used in the form of mixtures with one another.
The weight ratio of solvent to the sum of the reactants is customarily in the range of from 0.001 to 20% by weight, preferably from 0.001 to 10% by weight.
In an especially preferred embodiment of the process according to the invention, a compound of formula (XXII), (XXIIa), (XXIII) or (XXIV), preferably of formula (XXII), is reacted with a compound (XXI).
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
It has also proved to be extremely advantageous to carry out the process according to the invention in the presence of an oxidising agent, for example para-chloranil, in order to rearomatise the addition product.
The perylenebisimides of formula (XXI) are known or can be prepared according to known methods as described in Heterocycles (1995), 40, 477-500, for example by reacting a perylenebisanhydride with a primary amine to form a perylenebisimide.
The present invention relates also to a process for the preparation of perylenebisimides (II) wherein A2 is an organic radical of formula (III), (IV) or (V) and A1 is (V), by Diels-Alder reaction of a diene with a dienophile at elevated temperature, wherein a perylenebisimide of formula (XXI) is reacted with a compound of formula (XXII), (XXIIa), (XXIII), or (XXIV), or perylenebisimides of formula (XVI) are reacted with compounds of formula (XXII), (XXIIa) or (XXIII).
The reaction parameters generally correspond to those in the Diels-Alder reaction described above.
The compounds of formulae (XXII), (XXIIa), (XXIII) and (XXIV) are generally used in excess, preferably in a molar ratio of the compounds ((XXII) or (XXIIa) or (XXIII) or XXIV)):((XXI) or (XVI)) in a range of from 2.1:1 to 50:1, especially from 1.3:1 to 15:1.
The order in which the starting materials (XXI), (XXII), (XXIIa), (XXIII) or (XXIV) are added is generally not important. It has, however, proved advantageous to use the compound of formula (XXI) as the initial charge and then to add the compounds (XXII), (XXIIa), (XXIII) or (XXIV).
The perylenebisimides (I) and (II) prepared according to the Diels-Alder reactions according to the invention can be purified and isolated in accordance with customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation (e.g. analogously to the method described in Chem. Ber. 118 (1985) 4641-4645)).
Generally the perylenebisimides (I) and (II) can be used after purification and isolation directly for further reactions.
The present invention accordingly relates also to a process for the preparation of perylenebisimides of formula (IXa), (IXb) or (X), wherein the compound of formula (VII) is reacted with
a) NH3 or amidosulfuric acid, or
b) a primary amine of formula (XXV) H2Nxe2x80x94R4, or
c) a primary diamine of formula (XXVI) 
The amine (XXV) or (XXVI) or NH3 or amidosulfuric acid is generally used in excess, preferably in a molar ratio of the perylenebisimide (I) to (XXV) or (XXVI) or NH3 or amidosulfuric acid in a range of from 1:1.1 to 1:20, especially in the range of from 1:1.3 to 1:15.
The reaction is preferably carried out at reaction temperatures in the range of from 80 to 200xc2x0 C. According to observations hitherto, the success of the reaction is not dependent upon the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 40 hours, especially in the range of from 2 hours to 25 hours.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those mentioned above. Special preference is given to nitrogen-containing solvents, especially quinoline, and halogenated aliphatic hydrocarbons, such as trichloromethane.
The weight ratio of the sum of the reactants to the solvent is customarily in the range of from 100 to 0.001% by weight, preferably from 50:0.001% by weight.
A preferred embodiment of the process according to the invention relates to the reaction in the presence of N,Nxe2x80x2-dicyclohexylcarbodiimide (DCC) in trichloromethane.
An especially preferred embodiment of the process according to the invention relates to the reaction in the presence of N,Nxe2x80x2-dicyclohexylcarbodiimide (DCC) and trifluoroacetic acid in trichloromethane.
The molar ratio of DCC to the compound (VII) is customarily in the range of from 20:1 to 1:1, preferably from 15:1 to 1:1 and very especially in the range of from 10:1 to 1:1.
The molar ratio of trifluoroacetic acid to the compound (VIII) is customarily in the range of from 0.0001:100 to 0.1:10.
In a preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
It has also been found that the compound (VII) can be converted into a dicarboxylic acid derivative (XXVIIa) 
and by esterification into the dicarboxylic acid ester of formula (XXVIIb) 
wherein R5 is C1-C24alkyl or C1-C24cycloalkyl.
A further embodiment of the present invention accordingly relates also to a process for the preparation of compounds of formula (XXVIIa) by hydrolysis of an anhydride, wherein the compound (VIII) is used as anhydride and is reacted with an acid or a base, preferably in an aqueous medium.
The hydrolysis of anhydrides is known and is described, for example, in Survey of Organic Syntheses, by Calvin A. Buehler and Donald E. Pearson, Wiley-Interscience, USA, (1970).
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 200xc2x0 C., especially from 0 to 150xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 24 hours.
As acid there may be used, for example, an inorganic acid, such as hydrochloric acid, sulfuric acid, Lewis acids, such as boron trifluoride, or organic acids, such as methanesulfonic acids, formic acid or para-toluenesulfonic acid.
As bases there may be used, for example, alkali metal alcoholates, such as sodium or potassium methanolate or sodium or potassium ethanolate, and alkali metal carbonates and alkali metal hydrogen carbonates, such as sodium carbonate or potassium carbonate, and sodium hydrogen carbonate or potassium hydrogen carbonate, and alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, especially potassium hydroxide powder (85% by weight potassium hydroxide and 15% by weight water), and also lithium aluminium hydride, potassium tert-butanolate, triethylamine, aluminium alkanolate and also non-nucleophilic bases, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene ((DBN) or N,N,Nxe2x80x2,Nxe2x80x2-tetramethylethylenediamine (TMEDA).
The acid or base is generally used in a molar ratio of acid or base to compound (VIII) in the range of from 0.1:1 to 20:1.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those mentioned above.
The weight ratio of the sum of the reactants to the solvent is customarily in the range of from 0.001 to 20% by weight, preferably from 0.001 to 10% by weight.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The present invention relates also to a process for the preparation of diester derivatives (XXVIIb) by esterification of a dicarboxylic acid, wherein a compound of formula (XXVIIa) is reacted with an alcohol of formula (XXVIII), HO-R5, or with an alkyl halide of formula (XXIX), Hal-R5, in the presence of an acid or a base.
Suitable bases and acids are those mentioned above.
Methods for the esterification of carboxylic acids are known and described, for example, in Survey of Organic Synthesis, (1970).
A particular embodiment of the process according to the invention relates to the reaction with a base. Non-nucleophilic bases in particular have proved to be advantageous.
Generally the molar ratio of base to compound (XVIIa) is in the range of from 100:1 to 1:100, preferably in the range of from 20:1 to 1:20.
The molar ratio of alkyl halide to base is generally in the range of from 5:1 to 1:5, preferably in the range of from 2:1 to 1:2.
It has proved advantageous to carry out the reaction according to the invention in the presence of solvents. Suitable solvents are those mentioned above.
Generally the solvent is used in an amount sufficient to dissolve the compound (XVIIa).
It has also been found that the dicarboxylic acid derivatives (XVIIa) and anhydrides of formula (VII) can be decarboxylated.
The present invention accordingly relates also to a process for the preparation of perylenebisimides of formula (XI), by decarboxylation of a dicarboxylic acid or an anhydride with copper or a copper-containing compound, wherein a compound of formula (XXVIIa) or (VIII) is reacted in the presence of a solvent.
The decarboxylation of carboxylic acids can, as is known, be carried out with copper in the presence of quinoline (see Survey of Organic Synthesis, (1970), 144, 145 ).
Copper denotes, for example, copper powder, and as copper-containing compound there can be used copper(I) or copper(II) salts, preferably copper(I) or copper(II) oxide, copper chromite or copper sulfate; it is preferred to use copper powder.
Copper or a copper-containing compound is generally used in excess. The molar ratio of copper (or copper equivalent in copper-containing compounds) to the compound of formula (XVIIa) or (VIII) is preferably in the range of from 1.1:1 to 20:1, especially in the range of from 1.3:1 to 15:1.
The reaction is preferably carried out at reaction temperatures in the range of from 80 to 200xc2x0 C., especially from 120 to 180xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 48 hours, especially in the range of from 1 hour to 10 hours.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those mentioned above for the process for the preparation of the compound of formula (VII). Especially preferred solvents are nitrogen-containing solvents, with special preference being given to quinoline and 3-picoline.
The weight ratio of the sum of the reactants to the solvent is customarily in the range of from 0.001 to 20% by weight, preferably from 0.001 to 10% by weight.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The present invention relates also to perylenebisimides of formula (XXX) and to perylene monoanhydride-monoimides of formula (XXXI) 
wherein
R7 and R8 are each independently of the other hydrogen, NO2, PO(OR11)(OR12), Br, NH2 or N(R11R2)2, wherein
R11 and R12 are each independently of the other a radical mentioned under R2, and R9 and R10 are each independently of the other hydrogen, NO2, NH2 or N(R11R2)2.
Special preference is given to substituted perylenebisimides of formulae (XXXII) to (XXXIX), wherein especially R1 and R2 are each independently of the other 1-n-hexyl-1-heptyl, 2,5-di-tert-butylphenyl, 1-nonyl-1-decyl or 1-n-butyl-n-pentyl, 
and wherein preferably
R12 and R11 are unsubstituted or substituted C1-C4alkyl, especially methyl or ethyl, and wherein R1 and R2 are very especially 1-hexyl-1-heptyl or 1-butyl-pentyl, and 
and
wherein R1 and R2 are very especially 1-hexyl-1-heptyl, 2,5-di-tert-butylphenyl or 1-butylpentyl, and 
and
wherein R1 and R2 are very especially 1-hexyl-1-heptyl, and 
wherein R1 and R2 are very especially 1-hexyl-1-heptyl or 1-butyl-pentyl, and 
wherein R1 and R 2 are very especially 1-hexyl-1-heptyl or 1-butyl-pentyl, and 
wherein preferably
R11 and R3 are unsubstituted or substituted C1-C4alkyl, especially methyl or ethyl, and
wherein R1 is very especially 1-hexyl-1-heptyl or 1-butyl-pentyl, and 
wherein R1 is very especially 1-hexyl-1-heptyl or 1-butyl-pentyl.
Perylene monoanhydride-monoimides can be used as starting compounds in the preparation of perylenebisimides in close analogy to known methods. For example, Heterocycles (1995), 40, 477-500 describes how anhydride derivatives of perylenes can be reacted with primary amines to form the corresponding imides.
The anhydride derivatives according to the invention can also be used as fluorescent markers.
The nitro derivatives, especially monosubstituted derivatives, of derivatives of perylenetetracarboxylic acid have hitherto been obtainable only in unsatisfactory yields (see, for example, J. Org. Chem. USSR (Engl. Translation) 1980, 16, 762-766).
It has now been found that perylenebisimides of formula (XXI) and perylene monoanhydride-monoimides of formula (XXXI) wherein R9 and R10 are hydrogen can be substituted by a single nitro group in good yields.
The present invention accordingly relates also to a process for the preparation of compounds of formulae (XXXIII), (XXXVIII) and (XXXIX), wherein compounds of formula (XXI) or (XXXI) wherein R9 and R10 are hydrogen are reacted with N2O4 in the presence of a solvent.
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 40xc2x0 C., especially from 0 to 25xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 24 hours, especially in the range of from 2 hours to 10 hours.
The molar ratio of N2O4 to the compounds of formula (XXI) is customarily in the range of from 0.5:1 to 2:1, preferably from 0.8:1 to 1.5:1.
The molar ratio of N2O4 to the compounds of formula (XXXI) wherein R9 and R10 are hydrogen is customarily in the range of from 0.5:1 to 4:1, preferably from 0.8:1 to 1.5:1.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvents there come into consideration, for example, those solvents mentioned above for the process for the preparation of perylenebisimides (I) wherein A1 is A4. Especially preferred solvents are halogenated aliphatic hydrocarbons, such as especially dichloromethane.
A particular embodiment of the process according to the invention relates to the reaction in the presence of a catalyst.
As catalyst there are used, for example, acids, such as sulfonic acids, trifluoroacetic acid, trifluoromethanesulfonic acid, methanesulfonic acid or toluenesulfonic acid, preferably methanesulfonic acid.
The molar ratio of catalyst to the compound of formula (XXI) or (XXXI) wherein R9 and R10 are hydrogen is customarily in the range of from 0.0001:1 to 1:1.
The molar ratio of solvent to the compound of formula (XXI) or (XXXI) wherein R9 and R10 are hydrogen is generally in the range of from 0.01:1 to 100:1, preferably from 0.1:1 to 50:1.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The compounds (XXXIII), (XXXVIII) and (XXXIX) prepared according to the nitration processes according to the invention can be purified and isolated according to customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation.
It has also been found that the nitro derivatives of formulae (XXXIII), (XXXVIII) and (XXXIX) can be converted to their amino derivatives by reduction.
The present invention accordingly relates also to a process for the preparation of compounds of formulae (XXXVa), (XXXVIa) and (XXXVIIa) wherein perylenebisimides of formulae (XXXIII), (XXXVIII) and (XXXIX) are reacted
a) with iron in the presence of an acid, or
b) with palladium in the presence of hydride transporters such as triethylamine/formic acid or triethylammonium formate, hydrazine or derivatives thereof, or phosphinic or phosphoric acid.
For example, it is known from Survey of Organic Syntheses, by Calvin A. Buehler and Donald E. Pearson, Wiley-Interscience, USA, (1970), 413 to 417, that nitro compounds can be reduced with iron under acid conditions or with palladium/carbon and hydrogen. Furthermore, reduction with palladium is described, in the presence of formic acid, in J. Chem. Soc. Perkin Trans,I, (1977), 443, and in the presence of triethylammonium formate, in J.Org.Chem.(1977), 42,3491.
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 150xc2x0 C., especially from 0 to 100xc2x0 C. According to observations hitherto, the success of the reaction is not dependent upon the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 5 minutes to 24 hours, especially in the range of from 5 minutes to 5 hours, very especially from 5 minutes to 2 hours.
As acid there is customarily used an inorganic or organic acid. Preference is generally given to the use of an inorganic acid, for example hydrochloric acid, especially concentrated hydrochloric acid.
The molar ratio of iron to (XXXIII), (XXXVIII) and (XXXIX) is customarily in the range of from 1:10 to 15:1, preferably from 1:1 to 10:1.
The weight ratio of acid to iron is generally in the range of from 0.001:1 to 100:1.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those listed above for the process for the preparation of perylenebisimides (I) wherein A1 is A4.
The weight ratio of (XXXIII), (XXXVIII) or (XXXIX) to the solvent used is customarily in the range of from 0.001 to 100% by weight, preferably from 0.001 to 20% by weight.
In a preferred embodiment of the process according to the invention, it has proved advantageous to use palladium/carbon instead of palladium.
The weight ratio of palladium/carbon (with 5% by weight palladium based on carbon) to (XXXIII), (XXXVIII) and (XXXIX) is generally in the range of from 0.01:1 to 1:1, preferably in the range of from 0.1:1 to 0.5:1 and very especially in the range of from 0.1:1 to 0.3:1.
The molar ratio of triethylamine to formic acid is customarily in the range of from 1:0.1 to 0.9:1, preferably in the region of 1:0.5 and especially in the region of 1:0.7.
The molar ratio of triethylamine or triethylammonium formate to (XXXIII), (XXXVIII) and (XXXIX) is customarily in the range of from 5:1 to 100:1.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The amino derivatives (XLII) and (XLIII) prepared according to the processes of the invention can be purified and isolated in accordance with customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation.
The present invention relates also to a process for the preparation of compounds of formulae (XXXV), (XXXVI) and (XXXVII), wherein the compounds of formula (XXXVa) or (XXXVla) and (XXXVIIa) are reacted with a base with alkyl halides of formula R""11-Hal and/or R3-Hal, wherein Hal is fluoride, chloride, bromide, iodide and R11 and R3 are each independently of the other hydrogen or C1-C24alkyl, C1-C24cycloalkyl, and R11 and R3 are preferably the same. Houben-Weyl, Methoden der Organischen Chemie, G. Thieme Verlag Stuttgart, 1957, 4th ed., Vol. 11, Pt, 1., Chap. 2 describes methods for alkylating amines.
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 150xc2x0 C., especially from 0 to 50xc2x0 C., very especially from 0 to 30xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 48 hours.
As base there is customarily used an inorganic base, such as, for example, an alkali metal hydroxide, such as potassium hydroxide, sodium hydroxide, or an alkali metal carbonate, such as sodium carbonate, potassium carbonate, or an alkali metal hydrogen carbonate, such as sodium hydrogen carbonate or potassium hydrogen carbonate. It has proved especially advantageous to use aqueous potassium hydroxide. The weight ratio of potassium hydroxide to water is generally in the range of from 0.0001:1 to 1:1.
The molar ratio of the base to the amino derivatives of formula (XXXVa) or (XXXVla) and (XXXVIIa) is customarily in the range of from 1:10 to 10:1, preferably from 1:5 to 5:1.
The molar ratio of R11-Hal to R3-Hal is generally in the range of from 1:100 to 100:1.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those solvents listed above in the process for the preparation of perylenebisimides (I) wherein A1 is A4.
The weight ratio of the sum of the reactants to the solvent is customarily in the range of from 0.001 to 100% by weight, preferably from 0.001 to 20% by weight.
A special development of the present reaction relates to the use of dipolar aprotic solvents.
It has proved especially advantageous to carry out the reaction in the presence of a dipolar aprotic solvent and a phase-transfer catalyst.
As phase-transfer catalyst there may be used, for example, triethylbenzylammonium chloride or triethylbenzylammonium bromide.
The molar ratio of phase-transfer catalyst to (XXXVa) or (XXXVIa) and (XXXVIIa) is customarily in the range of from 0.0001:1 to 0.8:1, preferably from 0.001:1 to 0.5:1.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The present invention accordingly relates also to a process for the preparation of compounds of formulae (XXXV) or (XXXVI) and (XXXVII) wherein R11 and R3 are alkyl, preferably methyl, wherein the compound of formula (XXXVa) or (XXXVIa) and (XXXVIIa) is reacted with HCHO or with a formaldehyde-providing compound in the presence of formic acid (Leuckart-Wallach reaction) and a solvent, or alkylated with an alkyl iodide and a phase-transfer catalyst, preferably methyl iodide in aqueous potassium hydroxide solution and triethylammonium chloride.
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 200xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 48 hours.
As formaldehyde-providing compound there may be used, for example, paraformaldehyde or trioxane. Formaldehyde can be used in the form of a gas or in the form of a formalin solution.
The molar ratio of formic acid to the compound of formula (XXXVa) or (XXXVIa) and (XXXVIIa) is customarily in the range of from 1:100 to 100:1.
The concentration of the formalin solution is generally from 35 to 37 per cent by weight.
The molar ratio of the formalin solution to the compounds of formulae (XXXVa) or (XXXVIa) and (XXXVI1a) is customarily in the range of from 1:1 to 100:1.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those solvents listed above for the process for the preparation of perylenebisimides (I) wherein A1 is A4. Particularly advantageous as solvent are N,Nxe2x80x2-dimethylformamide, N,Nxe2x80x2-dimethylacetamide, nitrobenzene and N-methylpyrrolidone.
The weight ratio of the compounds of formulae (XXXVa) or (XXXVIa) and (XXXVIIa) to the solvent is customarily selected in the range of from 0.001 to 100% by weight, preferably from 0.001 to 20% by weight.
A special development of the present reaction relates to the use of dipolar aprotic solvents.
As phase-transfer catalyst there may be used, for example, triethylbenzylammonium chloride or triethylbenzylammonium bromide.
The molar ratio of phase-transfer catalyst to compounds of formulae (XXXVa) or (XXXVIa) and (XXXVIIa) is customarily in the range of from 0.0001:1 to 0.8:1, preferably from 0.001:1 to 0.5:1.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The reaction product is preferably isolated by precipitation with water and subsequent filtration.
It has proved advantageous to adjust the precipitated reaction product in water to a pH value in the range of from 7.5 to 10 with a base.
As base there may be used, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate or potassium hydrogen carbonate.
The compounds of formulae (XXXVa) or (XXXVIa) and (XXXVIIa) isolated according to the processes of the invention can be purified in accordance with customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation.
In the present invention it has also been found that trialkylphosphonate derivatives (XXXII) and pyrrolo derivatives (XII) can be obtained from the above nitro derivatives of the compounds of formula (XXXIII) by reaction with trialkyl phosphite.
The present invention accordingly relates also to a process for the preparation of perylenebisimide trialkylphosphonates of formula (XXXII) and perylenebisimide pyrroles of formula (XII), wherein the compound of formula (XXXIII) is reacted with trialkyl phosphite of the formula P(OR 12(OR11)(OR5) wherein R12, R11 and R5 are as defined above and are especially C1-C4 alkyl.
Synthesis 1969, 11 to 17, describes methods for the reaction of amines with trialkyl phosphite, so that further details on the subject are superfluous.
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 150xc2x0 C., especially from 100 to 150xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 48 hours.
The molar ratio of the nitro derivative (XXXIII) to the trialkyl phosphite is customarily in the range of from 1:1 to 1:500, preferably from 1:10 to 1:200.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, those solvents listed above for the process for the preparation of perylenebisimides (I) wherein A1 is A4.
The weight ratio of nitro derivative (XXXIII) to solvent is customarily selected in the range of from 1 to 100% by weight.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
The pyrrolo and trialkylphosphonate derivatives of formulae (XXXII) and (XII) prepared according to the process of the invention can be purified and isolated in accordance with customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation.
It has proved especially advantageous to separate and purify the pyrrolo and trialkylphosphonate derivatives of formulae (XXXII) and (XII) by column chromatography using trichloromethane as eluant on aluminium oxide.
It has also been found that the pyrrolo derivatives of formula (XII) can be alkylated, benzylated or acylated.
The invention accordingly relates also to a process for the preparation of compounds of formula (XIII), wherein a compound of formula (XII) is reacted with a halide of formula R4-Hal, in the presence of a base.
The reaction is preferably carried out at reaction temperatures in the range of from -10 to 100xc2x0 C., especially from 0 to 50xc2x0 C., very especially from 0 to 30xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 48 hours.
As bases there may be used the bases listed above for the process for the preparation of compounds of formula (XXVII).
The molar ratio of base to pyrrolo derivatives of formula (XII) is customarily in the range of from 1:10 to 10:1, preferably from 1:5 to 5:1.
In a preferred embodiment of the process according to the invention, the reaction of a pyrrolo derivative of formula (XII) with a halide is carried out in the presence of a solvent.
A particular embodiment of the process according to the invention relates to the reaction in the presence of potassium hydroxide powder in the presence of a protic solvent. For example, alcohols, such as methanol, ethanol, propanol, isopropanol, n-, sec- or tert- butanol, n-, sec- or tert-pentanol, have proved to be especially advantageous as protic solvents.
In a further particular embodiment of the process according to the invention, there are used generally non-nucleophilic bases, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene ((DBN) or N,N,Nxe2x80x2,Nxe2x80x2-tetramethylethylenediamine (TMEDA).
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, the solvents listed above for the process for the preparation of perylenebisimides (I) wherein A1 is A4. Special preference is given to N,Nxe2x80x2-dimethylformamide, N,Nxe2x80x2-dimethylacetamide or N-methylpyrrolidone and to trichloroethane, dichloroethane, trichloromethane or dichloromethane; ethers are especially preferred, with special preference being given to tetrahydrofuran.
The weight ratio of pyrrolo derivative (XII) to solvent is customarily in the range of from 0.001 to 100% by weight, preferably from 0.001 to 20% by weight.
The pyrrolo compound derivatives isolated according to the processes of the invention can be purified in accordance with customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation.
It has also been found in the present invention that the perylenebisimides of formula (XXXIII) are suitable for the nucleus-extension of perylenebisimides with sulfur.
The present invention accordingly relates also to a process for the preparation of compounds of formulae (XIV) and (XV), wherein 1-nitro-perylenebisimides of formula (XXXIII) are reacted with sulfur in the presence of a solvent.
The reaction is preferably carried out at reaction temperatures in the range of from xe2x88x9210 to 200xc2x0 C., especially from 0 to 150xc2x0 C. According to observations hitherto, the success of the reaction is not dependent on the pressure range selected. For simplicity""s sake, the reaction is customarily carried out at atmospheric pressure, but it is also possible to select pressures in the range of from 10 kPa to 10 MPa. The reaction times are selected, depending on the reaction temperature chosen, preferably in the range of from 1 hour to 40 hours, especially in the range of from 5 hours to 24 hours.
It has proved advantageous to carry out the reaction in the presence of an organic solvent. As solvent there come into consideration, for example, the solvents listed above for the process for the preparation of perylenebisimides (I) wherein A1 is A4. Special preference is given to dipolar aprotic solvents, such as N,Nxe2x80x2-dimethylformamide, N,Nxe2x80x2-dimethylacetamide, nitrobenzene and N-methylpyrrolidone.
The weight ratio of solvent to the 1-nitroperylenebisimide of formula (XXXIII) is customarily in the range of from 1:1 to 1000:1, preferably from 1:10 to 500:1.
The molar ratio of sulfur to the 1-nitroperylenebisimide (XXXIII) is customarily in the range of from 10:0.1 to 0.9:1, preferably in the range of from 5:0.1 to 4:1.
In a further preferred embodiment, the reaction is carried out in a protective gas atmosphere. Preferred protective gases are, for example, nitrogen and the noble gases, such as helium or argon.
It has proved advantageous to treat the reaction mixture with dilute mineral acid, such as hydrochloric acid, at a temperature in the range of from 80 to 120xc2x0 C., especially from 90 to 110xc2x0 C., the desired product being precipitated.
If desired, the resulting precipitate can be washed with water and, if desired, the precipitate can be dried.
Furthermore, the precipitate, which may or may not have been dried, can be purified in accordance with customary methods, such as by chromatography, especially column chromatography, or crystallisation, especially extractive recrystallisation.
A further embodiment of the present invention relates to the use of the perylenes (I), (II), (XXX) and (XXXI) according to the invention as colourants, especially as pigments and dyes, in each case in accordance with methods generally known per se, preferably
(a) for melt colouration of polymers, it being possible to use as polymers polyvinyl chloride, cellulose acetate, polycarbonate, polyamide, polyurethane, polyimide, polybenzimidazole, melamine resin, silicone, polyester, polyether, polystyrene, polymethyl methacrylate, polyethylene, polypropylene, polyvinyl acetate, polyacrylonitrile, polybutadiene, polychlorobutadiene or polyisoprene, and the copolymers of the mentioned monomers;
(b) as vat dyes or mordant dyes, for example for dyeing natural materials and, especially, paper, wood, straw, leather, animal skins or natural fibre materials, such as cotton, wool, silk, jute, sisal, hemp, flax or animal hair (e.g. horsehair) and their conversion products, such as viscose fibres, nitrocellulose silk or copper rayon, preferred salts for mordanting being aluminium, chromium and iron salts;
(c) in the manufacture of paints, lacquers, especially automotive lacquers, coating compositions, paper dyes, printing inks, inks, especially for use in ink-jet printers, preferably in homogeneous solution as fluorescent inks, and for drawing and writing purposes, and in electrophotography, for example for dry-copying systems (Xerox process) and laser printers;
(d) for security-marking purposes, such as for cheques, cheque cards, bank notes, coupons, documents, identity papers and the like, where a particular, unmistakable colour impression is to be achieved;
(e) as an additive to colourants, such as pigments and dyes, in which a particular shade of colour is to be achieved; especially luminescent shades are preferred;
(f) for labelling objects for the purpose of mechanically recognising those objects by means of fluorescence, preference being given to the mechanical recognition of objects for sorting, for example for the recycling of plastics, with alpha-numerical printing or bar codes preferably being used;
(g) for frequency conversion of light, for example in order to make longer-wavelength, visible light from short-wavelength light, or for frequency doubling or frequency tripling of laser light in non-linear optics;
(h) for the production of passive display elements for a wide variety of display, information and labelling purposes, for example passive display elements, road signs and traffic signals, such as traffic lights;
(i) as starting material for supraconducting organic materials (via xcfx80-xcfx80 interactions, after doping with, for example, iodine there is usually obtained an intermediate charge delocalisation);
(j) for fluorescent labelling of solids;
(k) for decorative and artistic purposes;
(I) for tracer purposes, for example in biochemistry, medicine, technology and natural science, it being possible to link the colourants according to the invention covalently to substrates or via secondary valences, such as hydrogen bonds or hydrophobic interactions (adsorption); examples thereof are protein-dye combinations, antibody-dye combinations or DNA- or RNA-dye combinations,
(m) as fluorescent dyes in highly sensitive detection methods (see C. Aubert, J. Fxc3xcnfschilling, 1. Zschokke-Grxc3xa4nacher and H. Langhals, Z. Analyt. Chem. 1985, 320, 361), especially as fluorescent dyes in scintillators;
(n) as dyes or fluorescent dyes in optical light-collecting systems, in fluorescent quantum counters, in fluorescent solar collectors (see H. Langhals, Nachr. Chem. Tech. Lab. 1980, 28, 716), in fluorescence-activated displays (see W. Greubel and G. Baur, Elektronik 1977, 26, 6), in cold-light sources for light-induced polymerisation in the preparation of plastics, for materials"" testing, for example in the manufacture of semiconductor circuitry, for the investigation of microstructures of integrated semiconductor components, in photoconductors, in photographic processes, in display, illumination or image-converting systems in which excitation is effected by means of electrons, ions or UV radiation, for example in fluorescent displays, Braun tubes or in fluorescent tubes, as part of an integrated semiconductor circuit, which contain dyes as such or in conjunction with other semiconductors, for example in the form of an epitaxy, in chemiluminescent systems, for example in chemiluminescent light rods, in luminescent immunoassays or other luminescent detection methods, as highlighter inks, especially for lending visual prominence to text and drawings or other graphic products, for identifying signs and other objects where a particular visual colour impression is to be achieved, in dye lasers, preferably as fluorescent dyes for producing laser beams and as Q-switches;
(o) as rheology improvers and
(p) for modifying inorganic solids, such as aluminium oxide, silicon oxide, for example, in zeolite cages, titanium dioxide, tin oxide, magnesium oxide (xe2x80x9cxylolithxe2x80x9d), silicates, clay minerals, chalk-, gypsum- or cement-containing surfaces such as paints or plaster surfaces in which the free carboxyl function provides special adhesion to the surface, or
(q) as NIR dyes for information technologies.
In particular, the compounds wherein R1 and/or R2 is/are 1-butyl-pentyl, 1-hexyl-1-heptyl, 1-heptyl-1-octyl, 1-octyl-1-nonyl, 1-nonyl-1-decyl and 2,5-di-tert-butylphenyl are distinguished by their good solubility.